Adela Yabro Collins ( Biblical Research , 1981) notes that the identification of Rome as “Babylon” was not the only or the most obvious identification available to John. It appears in Jewish writing in 4 Ezra, the Syriac Apocalypse of Baruch, and the fifth book of the Sibylline Oracles. Collins notes, “In each case where it occurs in these three works, the context makes it abundantly clear why the name Babylon was chosen. Rome is called Babylon because her forces, like those of Babylon at an earlier time, destroyed the temple and Jerusalem. It is probable that the author of Revelation took over this identification from the Jews, and that it had already become traditional by the end of the first century.”

From this, she concludes, “The use of the name Babylon for Rome in Revelation is a rather weighty internal indication of the date. It is highly unlikely that the name would have been used before the destruction of the temple by Titus. This internal element then points decisively to a date after 70 CE.” She then uses this “decisive” indication of date to interpret the sequence of kings in Revelation 17, arguing that the “one who is” cannot be Galba, since that would put the book before 70.

Decisive, if John uses “Babylon” to mean “Rome.” What is Collins argument in favor of this identification? Only this: “Most commentators agree that Babylon is a symbolic name for Rome.”